Not applicable.
Not applicable.
The present invention relates generally to duct work for interior ventilation systems, and more particularly to a heating, ventilation, and air-conditioning air supply and return duct boot seal.
In structures generally, the typical heating, ventilation, and air-conditioning (HVAC) system includes a constellation of supply air ducts and return air ducts servicing a defined area. In residential construction the system ducts are designed to fit between the joists and studs of framing members and terminate in supply outlets and returns. The warm air supply outlets are typically located low in the floor near exterior walls or on low on exterior walls. Returns are generally placed above the occupied spaces, either high in the inside walls or in the ceilings of the occupied spaces. Most ducts are terminated by a sheet metal duct boot interposed between floor or ceiling joists. The duct boot almost invariably provides an imperfect seal and thus allows supply air to escape from the duct outside the conditioned air space.
It is customary in construction practice to install HVAC systems before or after framing and the installation of doors, windows, and wall and roof coverings, but prior to finishing interior walls, ceilings, floors, and interior trim. Vent grilles or other ornamental and functional covers placed on vent openings are usually one of the last items on a construction punch list, installed when the structure is effectively ready for occupancy. Thus, during the final stages of construction the air supply and return air ducts are generally left uncovered and are therefore vulnerable to contamination from debris, dust, scrap material, water, and various other contaminants in the construction zone. Furthermore, exposed vents pose an injury risk to workers on the site.
Accordingly, it would be desirable to have means to temporarily cover HVAC duct boots during construction. It would further be desirable to provide an improved seal at the vent opening. Ideally, in the interests of economy, it would be desirable to provide an HVAC duct boot cover that serves both purposes and may be installed during construction prior to interior finishing, which does not require complete removal before installation of vent grilles, and which improves the air seal at the vent opening. The present invention addresses the foregoing objects.
A few devices in the prior art are known to provide vent boot covers, including U.S. Pat. No. 4,712,343, to Dearing et al, which teaches a re-usable shield for temporarily covering and protecting interior vent openings in residential and commercial HVAC systems. The device includes a rectangular plate attached to or formed with a smaller rectangular block which are each sized and grooved to allow the shield to be universally used in all standard size floor and baseboard vent openings.
The device shown in Dearing must be removed in its entirety prior to installation of a floor or wall covering, and before use of the duct system by occupants. Thus it does not provide protection of the vent opening during finish operations, nor does it improve the vent opening seal during use.
U.S. Pat. No. 4,829,886, to Battaglin, which discloses a guard for insertion into a central heating duct system inlet or outlet. The device includes a top and bottom having disposed within the top thereof and extending towards the bottom thereof at least one recess, the recess having side walls extending from proximate the top to proximate the bottom of the guard mechanism, the side walls abutting at least one lateral flange proximate the top of the guard mechanism, each lateral flange extending laterally away from the recess proximate the top of the guard mechanism. Some of the side walls have a channel apparatus extending from the bottom of the guard mechanism to proximate the top of the guard mechanism and there at each channel continuing along the extension of a complimentary adjoining laterally extending flange whereat the channel terminates remote the recess. When the guard mechanism is inserted within an inlet or outlet of a ducting system, contaminants will be prevented from entering said system, but the circulation of air will be allowed through the channel apparatus disposed within the side walls and flanges of the guard mechanism. The mechanism is not removed after construction is complete.
The apparatus disclosed in Battaglin fundamentally alters the movement of air through the duct boot. Even if the channels are sufficiently large, air must pass around the recess, and therefore will exit or enter the vent only around the edges of the vent opening.
U.S. Pat. No. 5,180,331, to Daw et al, shows a device attachable to a suspended floor member for collecting materials which fall through grid openings in the floor member and for controlling the rate of airflow through the grid openings in an adjustable manner. The device includes a spill container for positioning under the grid openings of the floor member in a coordinated position such that a venting path is provided for permitting airflow past the spill container from above the floor member while retaining the capacity to collect liquids and particulate matter flowing through the grid openings. Adjustable dampening structure is coupled with the spill member to provide selection of differing vent openings to control rate of airflow through the structure.
The device shown in Daw et al is complex and involves numerous component parts. It is impracticable for use only as a protective cover during construction.
U.S. Pat. No. 6,461,235 to Rutler et al, discloses a temporary vent opening cover that may be secured over a vent opening during building construction to prevent debris from entering the vent opening and accumulating in the system duct work. The cover includes a generally flat cover plate sized and shaped to cover the vent opening and spaced outwardly from the surface when the vent opening cover is secured over the vent opening. Air passages allow air to flow past the cover plate between the duct work and the workspace. A layer of air filter material covers the air passages and prevents debris from passing through.
As with Dearing et al and Daw et al, the device shown in Rutler requires removal prior to use of the venting system by final building occupants.
None of the foregoing patents discloses, teaches, or suggests a single-piece temporary vent boot cover that is removable, in part, prior to use, but which provides an improved vent seal after finish construction is complete.
The HVAC duct boot seal of the present invention comprises***
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FIG. 1 is a partial cross-sectional perspective view of a first preferred embodiment of the HVAC duct boot seal of the present invention;
FIG. 2 is a perspective view of the apparatus of FIG. 1;
FIG. 3 is a cross-sectional end view in elevation of the apparatus of FIGS. 1 and 2;
FIG. 4 is a cross-sectional side view in elevation of the apparatus of FIGS. 1-3;
FIG. 5 is a partial cross-sectional perspective view of a second preferred embodiment of the HVAC duct boot seal of the present invention, shown installed in a floor space between subfloor and a floor covering;
FIG. 6 is a perspective view of the apparatus of FIG. 5;
FIG. 7 is a cross-sectional side view in elevation of the apparatus of FIGS. 5 and 6; and
FIG. 8 is a cross-sectional end view in elevation of the apparatus of FIGS. 5-7.